Symantec learned of the malware while monitoring chat rooms used by the gaming community. Users who are worried about the eboot.pbp files they run can use PSafeP v1.1, an application by Dark Killer that aims to combat malicious homebrew. Check it out on PSPUpdates.
Update 2005-10-20: Our user igounfaze informed us that Symantec's anti-virus software deletes the overflow.tif regardless of its contents. Even the "valid" ones that are used for downgrading PSP v2.0 to v1.50 are identified as malicious by the software. What's even more strange is that Symantec's software does not care about the two other files (h.bin and index.dat), and that the overflow.tif cannot be ignored or put in the exclusions list.
Source:
Reuters